Preparation of 2-aminobenzene-1,4-disulfonic acid
300 g of nitrobenzene-2,5-disulfonic acid, are added in small portions over the course of about 1 hour to a boiling, well-stirred mixture of 200 grams of iron powder, 1 liter of water, and 20 ml. glacial acetic acid. Stirring and boiling are continued for about 30 minutes, replacing the water lost by evaporation. The mixture is then made alkaline with about 30 grams of sodium carbonate and filtered hot to remove the iron sludge. The residue is boiled with a small amount of water and filtered, this process being repeated until the filtrate gives only a small amount of dye when it is diazotized and treated with an alkaline solution of beta-naphthol or R salt. The combined filtrate and washings are made just acid to litmus by the addition of concentrated hydrochloric acid, and then evaporated to about 800 ml. 60 grams of solid salt is now added and the solution is made strongly acid by the addition of 200 ml. concentrated hydrochloric acid, after which it is cooled overnight. The colorless white paste is filtered with suction and the precipitate washed with saturated salt solution, pressed out, dried and pulverized. In this way is obtained about 210 to 220 grams of the monosodium salt of aniline-2,5-disulfonic acid in the form of a white powder.
The fundamental processes of dye chemistry, by H. E. Fierz-David, 106-107, 1949
2-Amino-1,4-benzenedisulfonic acid, 98-44-2, 2-Aminobenzene-1,4-disulfonic acid, Aniline-2,5-disulfonic acid, 2,5-Disulfoaniline, 4-Sulfometanilic acid, p-Benzenedisulfonic acid, 2-amino-, 2,5-Disulfo-1-aminobenzene, 2-Amino-1,4-disulfobenzene, 1-Anilino-2,5-disulfonic acid, 2-Amino-p-benzenedisulfonic acid, 1,4-BENZENEDISULFONIC ACID, 2-AMINO-, 1-Amino-2,5-benzenedisulfonic acid, 2-Aminobenzene-1,4-disulphonic acid, UNII-5E2OT6T2PS, 5E2OT6T2PS, Kyselina anilin-2,5-disulfonova, NSC 5580, 1-Aminobenzene-2,5-disulfonic acid, EINECS 202-669-6, BRN 2660550, Kyselina anilin-2,5-disulfonova [Czech], AI3-23218, ST50307837, ACMC-209sad, AC1L1UAR, WLN: WSQR BZ DSWQ, DSSTox_CID_24751, DSSTox_RID_80444, DSSTox_GSID_44751, Aniline 2,5-disulfonic acid, aniline 2,5 disulphonic acid, SCHEMBL149375, CHEMBL3184682, CTK3I6652, NSC5580, LDCCBULMAFILCT-UHFFFAOYSA-N, MolPort-004-959-721, 2-Amino-1,4-benzenedisulfonicacid, NSC-5580, ZINC1687023, 2,5-DISULFOANILINE, 95%, Tox21_301960, ANW-40931, KM3472, AKOS015854615, MCULE-8003621945, RTR-030323, CAS-98-44-2, TRA-0189553, NCGC00256123-01, AJ-29878, AK-96036, LS-30045, OR013802, OR174695, DB-057728, KB-166931, TR-030323, FT-0607352, ST24027760, EC 202-669-6, 3-14-00-02260 (Beilstein Handbook Reference), 3B3-052062
1, 2-amino-, C6H7NO6S2, CID60988, 3-aminobenzene-1,2-disulfonic acid